Her mother had it and she paved the way for Mary with her genes and a childhood of sweets.
"I grew up in a family where love equated baked goods. I came home to cookies and brownies and cake every day with a mom who stayed at home," said Heafy.
It's an all too familiar American tale and now Mary joins 18 million other Americans in what some are calling the most urgent public health crisis of our time a diabetes epidemic racking up 800,000 new cases every year.
CBS News Medical Correspondent Elizabeth Kaledin reports that obesity, inactivity and aging are to blame for this disease, in which the body basically loses its ability to produce insulin the hormone responsible for breaking down sugars.
"For every pound you gain you need more insulin to do it's job. Those people who get diabetes just don't make enough insulin and need more," said Dr. David Nathan, head of the Diabetes Center at Boston's Mass General Hospital.
"Diabetes doesn't come in a mild flavor. Diabetes causes significant problems over a lifetime," he said.
Kidney disease, stroke, circulation and vision problems, and heart disease can all be linked directly to Type 2 diabetes. Seventy-five percent of people with Type 2 diabetes die of cardiovascular disease.
"In the short term it seems to help lower their blood sugar for example. What we don't know is whether it has a long-term beneficial effect. We're trying to determine whether these lifestyle changes in fact decrease the amount of heart disease people have," explained Dr. Nathan.
Mary Heafy is signing up.
"The structure of being in this program I think will allow me to sty well and to reduce the chances of long term major illnesses," she said.
Drugs and insulin are widely available to treat diabetes, but doctors warn there can be no magic pill to reverse what decades of poor diet and inactivity are doing to the nation's health.
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